I was a user of 1Password for a few years. I was on version 3 (I guess - old logo and layout) on iPhone, same for OS X. I backed up all my data into the iCloud on iOS. I sold my iPhone 5 and when I was setting up the iPhone 6, I don't have access anymore to 1Password old version and the new one can't read my data. Same for the Mac.
The only access that I have to try to restore the data is the iCloud e-mail and password. I Guess the data are there.
How can I be sure?